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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        /**
         * map对已有数组进行加工
         */
        const arr = [1, 2, 3]
        const arr2 = arr.map(item => item * 10)
        console.log(arr2);
    </script>
</body>
</html>